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N. A. Emelyanov

Publications and source records attributed to N. A. Emelyanov.

3 recordsLinked to original sources

The skin effect in anomalous transport of charged particles in plasma with a microturbulent magnetic field. I. Isotropic plasma

The influence of electromagnetic skin effect on anomalous charged particle transport in dense, non-relativistic, collisionless plasma with a small-scale turbulent magnetic field was investigated using quasi-linear kinetic equations, through both analytical and numerical methods. Analytical expressions for the diffusion tensor components in the Fokker-Planck equation that take this effect into account have been found. The equation was solved numerically in the case of magnetostatic turbulence. It has been demonstrated that the skin effect increases the mean free path of particles in turbulent plasma, thereby reducing its anomalous resistance. It also leads to anisotropy in particle scattering, resulting in anisotropy in their stationary velocity distribution, which increases as the screening parameter grows. Approximate analytical formulas for the effective mobility of charged particles and the electric conductivity of plasma with isotropic magnetostatic turbulence have been obtained.

physics.plasm-ph↗

Explosive growth of large-scale magnetic fluctuations due to particle scattering on developed small-scale Weibel turbulence in magnetoactive plasma

The analytical theory of non-linear generation of large-scale magnetic turbulence in anisotropic magnetoactive plasma in the quasilinear approximation without taking into account the direct non-linear interaction of individual harmonics is constructed. It is shown that anomalous collisions of particles due to scattering on small-scale fluctuations of the developed Weibel turbulence lead to instability of long-wave harmonics, which are stable in the linear approximation. The non-linear growth of such harmonics at a given anisotropy of the particle velocity distribution, consistent with the dynamics of short-wave perturbations at the saturation stage and possible anisotropic particle injection, occurs in the superexponential regime and corresponds to an explosive-type instability. The growth law of the large-scale magnetic field is found analytically and the critical time of explosive instability is estimated.

physics.plasm-ph↗

Alfvén pulse at chromospheric footpoints of magnetic loops and generation of the super-Dreicer electric field

A self-similar solution of the linearised magnetohydrodynamic equations describing the propagation of the Alfvén pulse in an axially symmetric magnetic tube of variable diameter is obtained. The electric field component induced by the non-linear Alfvén wave and directed along the tube surface, i.e., accelerating particles along the magnetic field, is determined on the basis of the perturbation theory and specified to the case of a magnetic flux tube homogeneous over its cross section. For the chromospheric tubes, whose configuration is given by the barometric law of plasma pressure decrease, the conditions for achieving the super-Dreicer electric field limit necessary to drive the accelerated high-energy electrons into the coronal part of the loop are established.

physics.plasm-ph↗